[BUG] Fragmented Files in RO-Crate Export

[floWetzels]

When exporting to an RO-Crate, data files that are only linked by Processes via data fragments do not have a corresponding data entity in the RO-Crate. Furthermore, file paths are not relative to the RO-Crate root.

For example, in the export of the ArcPrototype, there are data entities with "@id": "proteomics_result.csv#col=1", "@id": "proteomics_result.csv#col=2", etc. However, there is no data entity with "@id": "proteomics_result.csv". There should be a data entity with "@id": "assays/measurement1/dataset/proteomics_result.csv" pointing to "@id": "assays/measurement1/dataset/proteomics_result.csv#col=1" through hasPart.